Volar fixation system with articulating stabilization pegs

ABSTRACT

A volar fixation system includes a T-shaped plate intended to be positioned against the volar side of the radial bone, a plurality of bone screws for securing the plate along an non-fractured portion of the radial bone, and a plurality of bone pegs which extend from the plate and into bone fragments of a Colles&#39; fracture. The plate is a T-shaped plate including a plurality of screw holes and a plurality of threaded peg holes. According to a preferred aspect of the invention, pegs can be articulated through a range of angles within respective peg holes and fixed at a desired angle within the range. The volar plate is positioned against the radius and screws are inserted through the screw holes to secure the volar plate to the radius. The bone fragments are aligned, and the holes are drilled through the peg holes into the fragments. The pegs are inserted through the peg holes and into the drilled holes in the bone. The pegs can be oriented at various angles relative to an axis normal to the lower surface of the plate. For each peg, once the peg has been appropriately positioned within the peg hole, a set screw is thread into the peg hole and tightened, thereby securing the peg in the selected orientation.

[0001] This application is a continuation-in-part of both U.S. patentapplication Ser. No. 09/524,058, field Mar. 13, 2000 and U.S. patentapplication Ser. No. 09/495,854, filed Feb. 1, 2000, which are eachhereby incorporated by reference herein in their entireties.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates broadly to surgical devices. Moreparticularly, this invention relates to a bone fixation system, andparticularly to a fixation system adapted to fixate a Colles' (or distalradial) fracture.

[0004] 2. State of the Art

[0005] Referring to FIG. 1, a Colles' fracture is a fracture resultingfrom compressive forces being placed on the distal radius 10, and whichcauses backward displacement of the distal fragment 12 and radialdeviation of the hand at the wrist 14. Often, a Colles' fracture willresult in multiple bone fragments 16, 18, 20 which are movable and outof alignment relative to each other. If not properly treated, suchfractures result in permanent wrist deformity. It is therefore importantto align the fracture and fixate the bones relative to each other sothat proper healing may occur.

[0006] Alignment and fixation are typically performed by one of severalmethods: casting, external fixation, interosseous wiring, and plating.Casting is non-invasive, but may not be able to maintain alignment ofthe fracture where many bone fragments exist. Therefore, as analternative, external fixators may be used. External fixators utilize amethod known as ligamentotaxis, which provides distraction forces acrossthe joint and permits the fracture to be aligned based upon the tensionplaced on the surrounding ligaments. However, while external fixatorscan maintain the position of the wrist bones, it may nevertheless bedifficult in certain fractures to first provide the bones in properalignment. In addition, external fixators are often not suitable forfractures resulting in multiple bone fragments. Interosseous wiring isan invasive procedure whereby screws are positioned into the variousfragments and the screws are then wired together as bracing. This is adifficult and time consuming procedure. Moreover, unless the bracing isquite complex, the fracture may not be properly stabilized. Platingutilizes a stabilizing metal plate typically against the dorsal side ofthe bones, and a set of parallel pins extending from the plate into theholes drilled in the bone fragments to provide stabilized fixation ofthe fragments. However, the currently available plate systems fail toprovide desirable alignment and stabilization.

SUMMARY OF THE INVENTION

[0007] It is therefore an object of the invention to provide an improvedfixation and alignment system for a Colles' fracture.

[0008] It is another object of the invention to provide a volar fixationsystem which desirably aligns and stabilizes multiple bone fragments ina distal radial fracture to permit proper healing.

[0009] It is also an object of the invention to provide a volar fixationsystem which is highly adjustable to provide a customizable frameworkfor bone fragment stabilization.

[0010] In accord with these objects, which will be discussed in detailbelow, a volar fixation system is provided which generally includes aT-shaped plate intended to be positioned against the volar side of theradial bone, a plurality of bone screws for securing the plate along anon-fractured portion of the radial bone, and a plurality of bone pegswhich extend from the plate and into bone fragments of a Colles'fracture.

[0011] The plate is generally a T-shaped plate defining an elongatebody, a head portion angled relative to the body, a first side which isintended to contact the bone, and a second side opposite the first side.The body portion includes a plurality of countersunk screw holes for theextension of the bone screws therethrough. The head portion includes aplurality of threaded peg holes for receiving the pegs therethrough.According to a first embodiment, the peg holes are preferablynon-linearly arranged. According to a second embodiment, the peg holesare preferably linearly arranged. In either embodiment, the peg holesare positioned increasingly distal in a medial to lateral directionalong the second side. According to a third embodiment, which preferablyuses a volar plate with peg holes arranged according to either of thefirst and second embodiments, the pegs are adjustable relative to thepeg holes and can be independently fixed in selectable orientations.

[0012] In use, the volar plate is positioned with its first side againstthe volar side of the radius and bone screws are inserted through thebone screw holes into the radius to secure the volar plate to theradius. The bone fragments are then aligned and the guide plate ispositioned on the second side of the volar plate. A drill drills holesinto the bone fragments.

[0013] The pegs are then inserted through the peg holes and into theholes in the bone. In some embodiments, the heads of the pegs arethreadably engaged in the volar plate. In other embodiments, the pegsare inserted into the peg holes and into the drilled holes at an anglechosen by the surgeon, and a set screw is inserted over each peg to lockthe peg in the volar plate at the chosen orientation. The volar fixationsystem thereby stabilizes and secures the bone fragments in their properorientation.

[0014] Additional objects and advantages of the invention will becomeapparent to those skilled in the art upon reference to the detaileddescription taken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is an illustration of an extremity subject to a Colles'fracture;

[0016]FIG. 2 is a top volar view of a right hand volar fixation systemaccording to a first embodiment of the invention;

[0017]FIG. 3 is a side view of a bone peg according to the firstembodiment of the volar fixation system of the invention;

[0018]FIG. 4 is a side view of a bone screw of the volar fixation systemof the invention;

[0019]FIG. 5 is a side view of the right hand volar plate of the volarfixation system according to the first embodiment of the invention;

[0020]FIG. 6 is a front end view of the right hand volar plate of thevolar fixation system according to the first embodiment of theinvention;

[0021]FIG. 7 is an exploded side view of the right hand volar plate andguide plate according to the first embodiment of the fixation system ofthe invention;

[0022]FIG. 8 is a side view of the guide plate positioned on the righthand volar plate to provide drill guide paths in accord with theinvention;

[0023]FIG. 9 is an illustration of the first embodiment of the volarfixation system provided in situ aligning and stabilizing a Colles'fracture;

[0024]FIG. 10 is a top volar view of a left hand volar fixation systemaccording to the second embodiment of the invention;

[0025]FIG. 11 is a lateral side view of the left hand volar fixationsystem according to the second embodiment of the invention;

[0026]FIG. 12 is a bottom view of the left hand volar fixation systemaccording to the second embodiment of the invention;

[0027]FIG. 13 is an enlarged side elevation of a bone peg according tothe second embodiment of the volar fixation system of the invention;

[0028]FIG. 14 is a proximal end view of the bone peg of FIG. 13;

[0029]FIG. 15 is first partial top view of the head portion of the lefthand volar plate according to the second embodiment of the volarfixation system of the invention;

[0030] FIGS. 16-19 are section views across line 16-16, 17-17, 18-18,and 19-19, respectively in FIG. 15;

[0031]FIG. 20 is second partial top view of the head portion of the lefthand volar plate according to the second embodiment of the volarfixation system of the invention;

[0032] FIGS. 21-24 are section views across line 21-21, 22-22, 23-23,and 24-24, respectively in FIG. 20;

[0033]FIG. 25 is a broken partial longitudinal section view across adistal end of a third embodiment of the volar fixation system of theinvention;

[0034]FIG. 26 is a proximal perspective view of a bone peg according tothe third embodiment of the invention; and

[0035]FIGS. 27 and 28 are proximal and distal perspective views,respectively, of a set screw according to the third embodiment of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] Turning now to FIGS. 2 through 4, a first embodiment of a volarfixation system 100 for aligning and stabilizing multiple bone fragmentsin a Colles' fracture generally includes a substantially rigid T-shapedplate 102 intended to be positioned against the volar side of the radialbone, a plurality of preferably self-tapping bone screws 104 forsecuring the plate 102 along a non-fractured portion of the radial bone,and a plurality of bone pegs 108 which extend from the plate 102 andinto bone fragments of a Colles' fracture.

[0037] Referring to FIGS. 2, 5 and 6, more particularly, the T-shapedplate 102 defines a head portion 116, an elongate body portion 118angled relative to the head portion, a first side 120 which is intendedto contact the bone, and a second side 122 opposite the first side. Thefirst side 120 at the head portion is preferably planar, as is the firstside at the body portion. As the head portion and body portion areangled relative to each other, the first side preferably defines twoplanar portions. The angle θ between the head portion 116 and the bodyportion 118 is preferably approximately 18° and bent at a radius ofapproximately 1.00 inch (FIG. 5). The distal edge 121 of the headportion 116 is preferably angled proximally toward the medial side at anangle α, e.g., 5°, relative to a line P, which is perpendicular to thebody portion. The head portion 116 preferably has a width of 0.913 inchand a greatest proximal-distal dimension (i.e., from the corner of angleα to the body portion) of approximately 0.69 inch, and the body portionpreferably has a width of 0.375 inch and a length of 1.40 inches. Theplate 102 preferably has a thickness of approximately 0.098 inch. Theplate 102 is preferably made from a titanium alloy, such as Ti-6A-4V.

[0038] The body portion 118 includes three preferably countersunk screwholes 124, 126, 128 for the extension of the bone screws 104therethrough. The first screw hole 124 has a center preferably 0.235inch from the end of the body portion, the second screw hole 126 has acenter preferably 0.630 inch from the end of the body portion, and thethird screw hole 128 is preferably generally elliptical (or oval) anddefines foci-like locations at 1.020 inches and 1.050 inches from theend of the body portion. The head portion 116 includes four threaded pegholes 130, 132, 134, 136 for individually receiving the pegs 108therethrough. According to a first preferred aspect of the firstembodiment of the invention, the peg holes 130, 132, 134, 136,preferably 0.100 inch in diameter, are preferably non-linearly arrangedalong the head portion 116, and are provided such that the adjacent pegholes are provided further distally in a medial to lateral directionalong the second side. More particularly, according to a preferredaspect of the first embodiment of the invention, the peg holes arepreferably arranged along a parabolic curve, with the center of peg hole130 located approximately 0.321 inch proximal line P and approximately0.719 inch medial of the lateral edge 137 of the head portion, thecenter of peg hole 132 located approximately 0.296 inch proximal line Pand approximately 0.544 inch medial of the lateral edge 137, the centerof peg hole 134 located approximately 0.250 inch proximal line P andapproximately 0.369 inch medial of the lateral edge 137, and the centerof peg hole 136 located approximately 0.191 inch proximal line P andapproximately 0.194 inch medial of the lateral edge 137.

[0039] In addition, according to a second preferred aspect of the firstembodiment of the invention, the peg holes define axes A₁, A₂, A₃, A₄which are oblique (not parallel) relative to each other, and morepreferably are angled in two dimensions (medial/lateral andproximal/distal) relative to each other; i.e., the pegs once insertedinto the peg holes are also angled in two dimensions relative to eachother. More particularly, the first axis A₁ of the first peg hole 130(that is, the most proximal and medial peg hole) is preferably directednormal to the first side 120 of the head portion 116. The axis A₂ of theadjacent peg hole 132, i.e., the second axis, is preferably angledapproximately 1-7° distal and lateral relative to the first axis A₁, andmore preferably approximately 2.5° distal and lateral relative to thefirst axis A₁. The axis A₃ of the peg hole 134 laterally adjacent thesecond peg hole 132, i.e., the third axis, is preferably angledapproximately 7-13° distal and lateral relative to the first axis A₁,and more preferably approximately 10° distal and lateral relative to thefirst axis A₁. The axis A₄ of the peg hole 134 laterally adjacent thethird peg hole 132, i.e., the fourth axis, is preferably angledapproximately 10-30° distal and lateral relative to the first axis A₁,and more preferably approximately 20° distal and lateral relative to thefirst axis A₁. The second side of the head portion 116, distal of thepeg holes 130, 132, 134, 136 is preferably beveled.

[0040] Referring back to FIG. 3, the pegs 108, preferably approximately0.872 inch in length, each have a threaded head 138 adapted tothreadably engage the threads about the peg holes 130, 132, 134, 136,and have a relatively smooth non-threaded cylindrical shaft 140. Theshafts 140 are preferably approximately 0.0675 inch in diameter and0.765 inch in length. Such dimensions permit the pegs to adequatelysupport the bone fragments such that the bone is able to heal correctly.The pegs 108 are also preferably made from titanium alloy, and may becoated in a ceramic, e.g., titanium nitride, to provide a bone interfacewhich will not adversely affect bone healing.

[0041] Turning now to FIGS. 7 and 8, the system 100 preferably alsoincludes a guide plate 146 which temporarily sits on the second side 122of the volar plate 102 and includes guide holes 148, 150, 152, 154(illustrated in overlapping section in FIG. 8) oriented according to theaxes A₁, A₂, A₃, A₄ of the peg holes for guiding a drill into the bonefragments at the required orientation. That is, the guide holes togetherwith the peg holes define a drill guide path along the axes withsufficient depth to accurately guide a drill (not shown) to drill holesat the desired pin orientations. The volar plate 102 and guide plate 146are also preferably provided with mating elements, such as a pluralityof holes 156, 158 on the second side of the volar plate (FIG. 2), and aplurality of protuberances 160 on the mating side of the guide plate(FIG. 7), to temporarily stabilize the guide plate on the volar plateduring the hole drilling process.

[0042] Referring to FIGS. 2 through 9, in use, the volar plate 102 ispositioned with its first side 120 against the volar side of the radius.Bone screws 104 (either self-tapping or inserted with the aid ofpre-drilled pilot holes) are inserted through the bone screw holes 124,126, 128 into the radius bone 10 to secure the volar plate 102 to theradius. The bone fragments 16, 18, 20 are then aligned with the radius10. Next, the guide plate 146 is positioned on the second side of thevolar plate. A drill, guided by a guide path formed by the peg holes andthe guide holes, drills holes into and between the bone fragments 16,18, 20 (and possibly also a portion of the integral radius, dependingupon the particular location and extent of the fracture), and the guideplate is then removed. The pegs 108 are then inserted through the pegholes 130, 132, 134, 136 and into the holes drilled into the fragments,and the heads of the pegs are threadably engaged in the volar plate. Thepegs 108, extending through the oblique-axis peg holes 130, 132, 134,136, are positioned immediately below the subcondylar bone of the radiusand support the bone fragments for proper healing. The volar fixationsystem thereby secures the bone fragments in their proper orientation.

[0043] Referring to FIGS. 10-12, a second embodiment of a volar plate210, substantially similar to the first embodiment (with like partshaving numbers incremented by 100) and used in substantially the samemanner as the first embodiment is shown, The plate 210 preferably has alength of approximately 2.35 inches, which is approximately 0.35 inchgreater than in the first embodiment. This additional lengthaccommodates an extra bone screw hole 229 in the body of the volar platesuch that the volar plate preferably includes four bone screw holes 224,226, 228, 229. The additional bone screw in screw hole 229 increasesplate stability over the three holes of the first embodiment. The plate210 preferably tapers in thickness from the body portion 218 to the headportion 216. A preferred taper provides a proximal body portion 218thickness of approximately 0.098 inch and head portion 216 thickness ofapproximately 0.078 inch. The taper decreases the thickness of the headportion 216 relative to the body such that the weight of the volar plateis reduced and an improved tendon clearance is provided. The distal edgeof the head portion 216 has an increased taper (preferably approximately600 relative to a line normal to the head) to a distal edge 221. Theedge 221 is broken (i.e., made blunt) to prevent irritation ordisturbance to the surrounding anatomy.

[0044] The head portion 216 includes four threaded peg holes 230, 232,234, 236 for individually receiving pegs 208 therethrough (FIGS. 13 and14), and a guide hole 256 for alignment of a guide plate. According to apreferred aspect of the second embodiment of the invention, the pegholes 230, 232, 234, 236, preferably 0.100 inch in diameter, arepreferably linearly arranged along the head portion 216, and areprovided such that the adjacent peg holes are provided further distallyin a medial to lateral direction along the first and second sides.Referring to FIG. 15, more particularly, according to a preferreddimensions of the second embodiment of the invention, the center of peghole 230 is located approximately 0.321 inch proximal line P andapproximately 0.750 inch medial of the lateral edge 237 of the headportion, the center of peg hole 232 is located approximately 0.306 inchproximal line P and 0.557 inch medial of the lateral edge 237, thecenter of peg hole 234 is located approximately 0.289 inch proximal lineP and approximately 0.364 inch medial of the lateral edge 237, and thecenter of peg hole 236 is located approximately 0.272 inch proximal lineP and approximately 0.171 inch medial of the lateral edge 237. As such,the distance from each of the peg holes to the distal edge 221 of thevolar plate is relatively greater than in the first embodiment, andprovides a preferred alignment with respect to the tapered distal edge221.

[0045] Referring to FIGS. 15-24, in addition, as in the firstembodiment, the peg holes define axes A₁, A₂/ A₃, A₄ which are obliquerelative to each other, and more preferably are angled in two dimensions(medial/lateral and proximal/distal) relative to each other; i.e., thepegs 208 once inserted into the peg holes are also angled in twodimensions relative to each other. More particularly, as in the firstembodiment, the first axis A₁ of the first peg hole 230 is preferablydirected normal (FIGS. 16 and 21) to the first side 220 of the headportion 216. The axis A₂ of peg hole 232 is preferably angledapproximately 1-7° distal (FIG. 17) and approximately 1-7° lateral (FIG.22) relative to the axis A₁. and more preferably approximately 2.5° bothdistal and lateral relative to axis A₁. The axis A₃ of peg hole 234 ispreferably angled approximately 7-13° distal (FIG. 18) and approximately7-13° lateral (FIG. 23) relative to axis A₁, and more preferablyapproximately 10° both distal and lateral relative to axis A₁. Axis A₄of the peg hole 234 is preferably angled approximately 10-30° distal(FIG. 19) and approximately 10-30° lateral (FIG. 24) relative to axisA₁, and more preferably approximately 20° both distal and lateralrelative to axis A₁.

[0046] Referring to FIGS. 13 and 16-19, each of the peg holes has acountersunk portion 270, 272, 274, 276, respectively, for receiving thehead 238 of peg 208. Countersunk portions 270, 272 are each preferablyapproximately 0.030 inch deep and threaded according to the head of thepegs, as described below. Countersunk portion 274 is preferablyapproximately 0.042 inch deep and likewise threaded. Countersunk portion276 is preferably approximately 0.056 inch deep and also threaded. Therespective depths of the countersunk portions are adapted to betteraccommodate the heads 238 of the pegs 208 relative to the respectiveaxes of the peg holes.

[0047] Referring to FIGS. 13 and 14, the pegs 208, preferablyapproximately 0.872 inch in length, each have a threaded head 238adapted to threadably engage threads about the peg holes 230, 232, 234,236, and have a relatively smooth non-threaded cylindrical shaft 240.The heads 238 preferably include a no. 5 thread 280 at a count of 44 perinch. In addition, the heads 238 are rounded and include a hex socket282 to facilitate stabilized threading into the peg holes. This designaccommodates the reduced thickness of the volar plate at the headportion 216. The shafts 240 are preferably approximately 0.0792 inch (2mm) in diameter and 0.765 inch in length. Such dimensions permit thepegs to adequately support the bone fragments such that the bone is ableto heal correctly. The pegs 208 are also preferably made from titaniumalloy, and are preferably ‘tiodized’ to provide a strong finish whichdoes not adversely affect bone healing.

[0048] Turning now to FIG. 25, a volar fixation system 300 according toa third embodiment is shown in which each peg can be articulated througha range of angles within a respective peg hole and fixed at a desiredangle within the range. The system includes a volar plate 302, four pegs308, and four set screws 310, as well as bone screws, not shown butdescribed above, for mounting the volar plate to the radius.

[0049] The volar plate 310 is substantially similar to the first orsecond embodiments, with the exception of the shape of the peg holesdescribed below, and is used in substantially the same manner as thefirst embodiment. Each peg hole 312 in the volar plate includes acylindrical upper bore 314 provided with threads 316 and a lower portion318 having a radius of curvature. The surface 320 of the lower portionand/or the surface 330 of the head of the peg is preferably roughened,e.g., by electrical, mechanical, or chemical abrasion, or by theapplication of a coating or material having a high coefficient offriction. The lower opening 322 of each peg hole includes acircumferential bevel 324.

[0050] Referring to FIGS. 25 and 26, each peg 308 includes a head 330and a cylindrical shaft 332. The proximal portion 334 of the head 330includes a cup 336 having an outer radius Ro substantially correspondingto the radius of the lower portion 318 of the peg holes 312, and arelatively smaller inner radius R_(i) of curvature. The head 330 definespreferably approximately 1600 of a sphere. The shaft 332 includes aslight taper 336 at the intersection with the head 330, and a roundeddistal end 338. According to a preferred manufacture of the pegs 308,the cylindrical shaft 332 is first provided with a sphere (not shown) ora hemispher (not shown) at a proximal end. If a sphere is provided, itis cut to a hemisphere. The hemisphere is then hollowed and furtherreduced to the 160° shape. Finally, the taper 336 is provided at theintersection.

[0051] Turning now to FIGS. 25, 27 and 28, each set screw 310 includes aproximal hex socket 340, circumferential threads 342 adapted to engagethe threads 316 of the upper bore 314 of the peg hole, and distalhemispherical portion 344 having substantially the same radius ofcurvature as the inner radius of curvature of the cup 336, andpreferably substantially smaller than a radius of the peg holes 312.

[0052] In accord with the third embodiment, the volar plate ispositioned on the radius, a hole is drilled through the elliptical screwhole on the volar plate and into the radius. A bone screw is insertedthrough the plate and into the bone. The fractured bones are thenadjusted under the plate into their desired stabilized positions, andthe bone screw is tightened. Then, through the peg holes, the surgeondrills holes into the fracture location for the stabilization pegs.Unlike the previous embodiments, the holes may be drilled at any anglewithin a predefined range, and preferably at any angle within a range of20° relative to an axis normal A_(N) to the lower surface of the head ofthe volar plate. Each hole may be drilled at the same angle or atrelatively different angles. After each hole is drilled, a peg 308 isinserted therein. The bevel 324 at the lower end 322 of the peg hole 312and the taper 336 on the shaft cooperate to permit the peg to beoriented with greater angularity relative to the axis A_(N), ifrequired, as interference between the peg hole and peg shaft is therebyreduced. Once the peg 308 has been appropriately positioned within thepeg hole, one of the set screws 310 is threaded into the upper bore 314of the peg hole 312. The hemispherical portion 344 contacts the head 330of the peg, seating in the concavity of the cup 336. As the set screw310 is tightened, the head of the peg, which may be roughened, issandwiched between the set screw and the roughened inner surface of thelower portion of the peg hole, thereby securing the peg in the selectedorientation. The other pegs are similarly positioned and angularlyfixed.

[0053] There have been described and illustrated herein embodiments of avolar fixation system and a method of aligning and stabilizing a Colles'fracture. While particular embodiments of the invention have beendescribed, it is not intended that the invention be limited thereto, asit is intended that the invention be as broad in scope as the art willallow and that the specification be read likewise. Thus, whileparticular materials for the elements of the system have been disclosed,it will be appreciated that other materials may be used as well. Inaddition, while a particular number of screw holes in the volar platesand bone screws have been described, it will be understood anothernumber of screw holes and screws may be provided. Further, fewer screwsthan the number of screw holes may be used to secure to the volar plateto the radius. Also, fewer or more peg holes and bone pegs may be used,preferably such that at least two pegs angled in two dimensions relativeto each other are provided. Moreover, while in the first embodiment itis preferred that the peg holes lie along a parabolic curve, it will beappreciated that they can lie along another curve. In addition, while aparticular preferred angle between the head portion and body portion hasbeen disclosed, other angles can also be used. Furthermore, whileparticular distances are disclosed between the peg holes and line P, itwill be appreciated that the peg holes may be provided at otherdistances relative thereto. Moreover, while particular preferredmedial/lateral and proximal/distal angles for the peg hole axes has beendisclosed, it will be appreciated that yet other angles may be used inaccord with the invention. Also, while a right-handed volar plate isdescribed with respect to the first embodiment, and a left-handed volarplate is described with respect to the second embodiment, it will beappreciated that each embodiment may be formed in either a right- orleft-handed model, with such alternate models being mirror images of themodels described. In addition, while a range of 200 in which the pinsmay articulate is disclosed, the peg holes and pegs may be modified topermit a greater or smaller range of articulation. Furthermore, while ahex socket is disclosed on the set screws for applying rotational forcethereto, it will be appreciated that other rotational engagement means,e.g., a Phillips, slotted, star, rectangular, or other configuration maybe used. In addition, aspects from each of the embodiments may becombined. It will therefore be appreciated by those skilled in the artthat yet other modifications could be made to the provided inventionwithout deviating from its spirit and scope as claimed.

1. A volar fixation system, comprising: (a) a substantially rigid plateincluding a distal head portion and a proximal body portion angledrelative to said head portion, said head portion defining a plurality ofpeg holes adapted to individually receive fixation pegs therethrough,said peg holes having an upper portion and a lower portion, said upperportion having a first thread, and said lower portion having sphericalradius of curvature, said body portion including at least one screwhole; (b) a plurality of pegs each having a head portion and a shaftportion, said shaft portion sized to be received in said peg holes, andsaid head portion having an outer surface with substantially a samespherical radius of curvature as said lower portion of said peg holes;and (c) a plurality of set screws each having a body including a secondthread rotationally engageable with said first thread, and a proximalrotational engagement means for engaging said set screw and applying arotational force thereto, wherein when said pegs are provided intorespective peg holes, each said peg may be positioned at any anglewithin a predefined range of angles relative to an axis normal to alower surface of said head portion of said volar plate, and once sopositioned, respective set screws when thread into said upper portionsof said peg holes fix said pegs in their respective angles.
 2. A volarfixation system according to claim 1 , wherein: said predefined rangeincludes 200 relative to said axis normal to said lower surface of saidhead portion of said volar plate.
 3. A volar fixation system accordingto claim 1 , wherein: said lower portion of each of said peg holes isprocessed to have a relatively high coefficient of friction.
 4. A volarfixation system according to claim 1 , wherein: said outer surface ofsaid head portion of each of said pegs is processed to have a relativelyhigh coefficient of friction.
 5. A volar fixation system according toclaim 1 , wherein: said peg holes are linearly arranged.
 6. A volarfixation system according to claim 1 , wherein: said head portiondefines a medial side and a lateral side, and said peg holes arearranged in a generally medial to lateral direction wherein successivelateral peg holes are situated distally relative to adjacent peg holes.7. A volar fixation system according to claim 1 , wherein: said pegholes lie along a curve.
 8. A volar fixation system according to claim 1, wherein: said head portion includes exactly four peg holes.
 9. A volarfixation system according to claim 1 , wherein: a taper is provided atan intersection of said head and shaft of each of said pegs.
 10. A volarfixation system according to claim 9 , wherein: a bevel is providedabout a lower opening of each of said peg holes.
 11. A volar fixationsystem according to claim 1 , wherein: each of said head portions ofsaid pegs is concave, and each of said set screws includes a distalconvex portion seating with said head portions.
 12. A volar fixationsystem according to claim 11 , wherein: said concave and convex portionsare each defined by a substantially same radius.
 13. A volar fixationsystem according to claim 1 , wherein: said outer surface of said headportion defines less than a hemisphere.
 14. A volar fixation systemaccording to claim 1 , wherein: said rotational engagement means of eachof said set screws is a hex socket.
 15. A volar fixation systemaccording to claim 1 , wherein: said shaft portion of each of said pegsis a non-threaded cylinder.
 16. A volar fixation plate, comprising: asubstantially rigid plate including a distal head portion and a proximalbody portion angled relative to said head portion, said head portiondefining a plurality of peg holes adapted to individually receivefixation pegs therethrough, said peg holes having an upper portion and alower portion, the lower portion having spherical radius of curvature,said body portion including at least one screw hole.
 17. A volarfixation plate according to claim 16 , wherein: said upper portionincludes a thread.
 18. A volar fixation plate according to claim 16 ,wherein: said lower portion is processed to have a relatively highcoefficient of friction.
 19. A volar fixation plate according to claim16 , wherein: said peg holes are linearly arranged.
 20. A volar fixationplate according to claim 16 , wherein: said head portion defines amedial side and a lateral side, and said peg holes are arranged in agenerally medial to lateral direction wherein successive lateral pegholes are situated distally relative to adjacent peg holes.
 21. A volarfixation plate according to claim 16 , wherein: said peg holes lie alonga curve.
 22. A volar fixation plate according to claim 16 , wherein:said head portion includes exactly four peg holes.
 23. A peg forinsertion into a peg hole in a fracture fixation system, comprising: (a)a head having an outer surface with a first substantially sphericalradius of curvature and a concavity with a second substantiallyspherical radius of curvature, said head defining less than ahemisphere; and (b) a cylindrical shaft coupled to said head, said shaftincluding a taper adjacent said head.
 24. A peg according to claim 23 ,wherein: said outer surface of said head portion is processed to have arelatively high coefficient of friction.
 25. A set screw for set a pegin a peg hole, comprising: a body including a thread, a proximalrotational engagement means for engaging said set screw and applying arotation force thereto, and a distal hemispherical portion.
 26. A setscrew according to claim 25 , wherein: said distal hemispherical portiondefines a radius smaller than a radius of said body.
 27. A set screwaccording to claim 25 , wherein: said rotational engagement means is ahex socket.